- • Spontaneous urethral discharge.
- • Burning with urination.
- • Purulent or mucoid exudate with urethral stripping.
- • More than 5 white blood cells (WBCs) per high-power
field of urethral exudate.
Urethral discharge is characterized by abnormal purulent or mucoid
secretions from the penis or, rarely, the female urethra. Urethral
discharge reflects inflammation of the urethra usually caused by
infection. Urethritis is defined as the presence of leukorrhea and
urethral inflammation. Clinically, urethritis in men is characterized
by urethral discharge and is often accompanied by dysuria. Leukorrhea
has been defined as the presence of more than 5 WBCs per high-power
field in a urethral swab specimen, using either Gram stain or other
cellular stain (eg, Wright or methylene blue).
Urethral discharge can occur in sexually active persons of all
ages but is most common in young adults, the age group in which
the prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae infection is
highest. High rates of urethritis also occur in men who have sex
with men. Urethral discharge occurs after urethral infection in
persons exposed to infectious agents during oral, vaginal, or anal
The most common etiology of urethral discharge is N gonorrhoeae, followed by C trachomatis. These two organisms
account for about 40% of cases of urethritis. Although
historically urethritis has been differentiated into gonococcal
urethritis versus nongonococcal urethritis (NGU), with the discovery
of additional causes of urethritis that dichotomy has little clinical
relevance. The other major putative organisms that have been associated
with sexually transmitted NGU include Mycoplasma
genitalium, Trichomonas vaginalis, herpes simplex virus, and
adenovirus (see Table 3–1). The role that Mycoplasma hominis and Ureaplasma urealyticum play
in urethritis remains unproven.
Table 3–1. Pathogens that Can Cause Sexually Transmitted Urethritis.a |Favorite Table|Download (.pdf)
Table 3–1. Pathogens that Can Cause Sexually Transmitted Urethritis.a
|Herpes simplex virus|
Urethral discharge is most commonly associated with gonorrhea.
Infection with these gram-negative diplococci can occur after oral,
vaginal, or anal intercourse, with symptoms developing between 1
and 3 days after exposure.
In early studies that largely relied on culture methods, Chlamydia was found to account for
a relatively small proportion of cases of NGU. In three large studies
performed at STD clinics in the 1980s and 1990s, Chlamydia was
identified in 19–31% of patients. On average one
third but in some studies up to 60% of patients with gonococcal
urethritis may have coinfection with C trachomatis.
This organism was first identified as a cause of NGU in 1981.
It is very difficult to grow in culture, and diagnostic surveys